Polyphenylene ether resin has good thermal resistance, high impact strength, and good dimensional stability. However, polyphenylene ether resin has poor processability due to its excessively high thermal resistance. Therefore, the polyphenylene ether resin is blended with a polystyrene resin which has good compatibility with polyphenylene ether resin to improve processability for use of housing materials in electrical apparatuses. However, the disadvantage could be observed that the blend of polyphenylene ether resin and polystyrene has poor impact strength. In order to overcome the shortcoming, a rubber-reinforced polystyrene resin is used instead of polystyrene resin. However, although the impact strength of the resin composition is improved, the resin has decreased molding property and poor surface gloss.
U.S. Pat. No. 3,383,435 discloses blends of polyphenylene ether and one or more styrene resins having improved processablity and chemical resistance. Further, U.S. Pat. No. 4,360,618 discloses a polyphenylene ether blended with SAN or ABS polymers containing from 2˜8% by weight of acrylonitrile. However, these resin compositions have insufficient appearance, impact strength, and molding property.
Accordingly, the present inventors have developed thermoplastic resin compositions which has a good surface gloss, impact strength, and molding property by adding a rubber-modified styrene-containing resin containing 0.5-10% by weight of acrylonitrile to a polyphenylene ether resin.